using GalaSoft.MvvmLight.Ioc;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using Tango.Core.Commands;
using Tango.Integration.Services;
using Tango.Logging;
using Tango.MachineStudio.Common;
using Tango.MachineStudio.Common.Authentication;
using Tango.MachineStudio.Common.Modules;
using Tango.MachineStudio.Common.Navigation;
using Tango.MachineStudio.Common.Notifications;
using Tango.MachineStudio.Common.StudioApplication;
using Tango.MachineStudio.UI.StudioApplication;
using Tango.MachineStudio.UI.SupervisingController;
using Tango.MachineStudio.UI.Views;
using Tango.MachineStudio.UI.Windows;
using Tango.PMR.Stubs;
using Tango.SharedUI;
using Tango.SharedUI.Helpers;
using Tango.Transport.Adapters;

namespace Tango.MachineStudio.UI.ViewModels
{
    /// <summary>
    /// Represents the Machine Studio main view, view model.
    /// </summary>
    /// <seealso cref="Tango.SharedUI.ViewModel{Tango.MachineStudio.UI.SupervisingController.IMainView}" />
    public class MainViewVM : ViewModel<IMainView>
    {
        private IStudioModule _currentModule;
        private INavigationManager _navigation;
        private bool _isDisconnecting;

        /// <summary>
        /// Gets or sets the current loaded module.
        /// </summary>
        public IStudioModule CurrentModule
        {
            get { return _currentModule; }
            set { _currentModule = value; RaisePropertyChangedAuto(); }
        }

        private bool _isModuleLoaded;
        /// <summary>
        /// Gets or sets a value indicating whether any module is loaded at the moment.
        /// </summary>
        public bool IsModuleLoaded
        {
            get { return _isModuleLoaded; }
            set { _isModuleLoaded = value; RaisePropertyChangedAuto(); }
        }

        private bool _isMenuOpened;
        /// <summary>
        /// Gets or sets a value indicating whether the side menu is opened.
        /// </summary>
        public bool IsMenuOpened
        {
            get { return _isMenuOpened; }
            set { _isMenuOpened = value; RaisePropertyChangedAuto(); }
        }

        /// <summary>
        /// Gets or sets the start module command.
        /// </summary>
        public RelayCommand<IStudioModule> StartModuleCommand { get; set; }

        /// <summary>
        /// Gets or sets the open module in window command.
        /// </summary>
        public RelayCommand<IStudioModule> OpenModuleInWindowCommand { get; set; }

        /// <summary>
        /// Gets or sets the home command.
        /// </summary>
        public RelayCommand HomeCommand { get; set; }

        /// <summary>
        /// Gets or sets the connect command.
        /// </summary>
        public RelayCommand ConnectCommand { get; set; }

        /// <summary>
        /// Gets or sets the disconnect command.
        /// </summary>
        public RelayCommand DisconnectCommand { get; set; }

        /// <summary>
        /// Gets or sets the sign-out command.
        /// </summary>
        public RelayCommand SignoutCommand { get; set; }

        private IAuthenticationProvider _authenticationProvider;
        /// <summary>
        /// Gets or sets the authentication provider.
        /// </summary>
        public IAuthenticationProvider AuthenticationProvider
        {
            get { return _authenticationProvider; }
            set { _authenticationProvider = value; RaisePropertyChangedAuto(); }
        }

        private IStudioModuleLoader _studioModuleLoader;
        /// <summary>
        /// Gets or sets the studio module loader.
        /// </summary>
        public IStudioModuleLoader StudioModuleLoader
        {
            get { return _studioModuleLoader; }
            set { _studioModuleLoader = value; RaisePropertyChangedAuto(); }
        }

        private INotificationProvider _notificationProvider;
        /// <summary>
        /// Gets or sets the notification provider.
        /// </summary>
        public INotificationProvider NotificationProvider
        {
            get { return _notificationProvider; }
            set { _notificationProvider = value; RaisePropertyChangedAuto(); }
        }

        private IStudioApplicationManager _applicationManager;
        /// <summary>
        /// Gets or sets the application manager.
        /// </summary>
        public IStudioApplicationManager ApplicationManager
        {
            get { return _applicationManager; }
            set { _applicationManager = value; RaisePropertyChangedAuto(); }
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="MainViewVM"/> class.
        /// </summary>
        /// <param name="view">The view.</param>
        /// <param name="authenticationProvider">The authentication provider.</param>
        /// <param name="studioModuleLoader">The studio module loader.</param>
        /// <param name="notificationProvider">The notification provider.</param>
        /// <param name="applicationManager">The application manager.</param>
        /// <param name="navigationManager">The navigation manager.</param>
        public MainViewVM(
            IMainView view,
            IAuthenticationProvider authenticationProvider,
            IStudioModuleLoader studioModuleLoader,
            INotificationProvider notificationProvider,
            IStudioApplicationManager applicationManager,
            INavigationManager navigationManager) : base(view)
        {
            _navigation = navigationManager;
            AuthenticationProvider = authenticationProvider;
            StudioModuleLoader = studioModuleLoader;
            NotificationProvider = notificationProvider;
            ApplicationManager = applicationManager;

            StartModuleCommand = new RelayCommand<IStudioModule>(StartModule);

            HomeCommand = new RelayCommand(Home);
            ConnectCommand = new RelayCommand(ConnectToMachine);
            SignoutCommand = new RelayCommand(SignOut);
            DisconnectCommand = new RelayCommand(DisconnectFromMachine, (x) => ApplicationManager.IsMachineConnected && !_isDisconnecting);
            OpenModuleInWindowCommand = new RelayCommand<IStudioModule>(OpenModuleInWindow);
        }

        /// <summary>
        /// Disconnected from the current connected machine.
        /// </summary>
        private async void DisconnectFromMachine()
        {
            using (_notificationProvider.PushTaskItem("Disconnecting from machine..."))
            {
                _isDisconnecting = true;
                InvalidateRelayCommands();
                await ApplicationManager.ConnectedMachine.Disconnect();
                ApplicationManager.ConnectedMachine = null;
                _isDisconnecting = false;
                InvalidateRelayCommands();
            }
        }

        /// <summary>
        /// Signs-out the current logged-in user.
        /// </summary>
        private void SignOut()
        {
            _authenticationProvider.Logout();
            _navigation.NavigateTo(NavigationView.LoginView);
            CurrentModule = null;
            IsMenuOpened = false;
        }

        /// <summary>
        /// Opens the machine connection dialog to allow the user to scan and connect to remote machines view USB/TCP.
        /// </summary>
        private void ConnectToMachine()
        {
            _notificationProvider.ShowModalDialog<MachineConnectionViewVM>(async (x) =>
            {
                if (x.SelectedMachine != null)
                {
                    if (ApplicationManager.IsMachineConnected)
                    {
                        using (_notificationProvider.PushTaskItem("Disconnecting..."))
                        {
                            await ApplicationManager.ConnectedMachine.Disconnect();
                            await Task.Delay(1000);
                        }
                    }

                    if (x.SelectedMachine.RequiresAuthentication)
                    {
                        _notificationProvider.ShowModalDialog<MachineLoginViewVM>(async (login) =>
                        {
                            using (NotificationProvider.PushTaskItem("Connecting to machine " + x.SelectedMachine.ToString() + "..."))
                            {
                                try
                                {
                                    await x.SelectedMachine.Connect();

                                    var authenticated = await x.SelectedMachine.As<IExternalBridgeSecureClient>().Authenticate(login.Password);
                                    if (!authenticated)
                                    {
                                        _notificationProvider.ShowError("It seems like you are not authorized to access the selected machine.");
                                    }
                                    else
                                    {
                                        ApplicationManager.ConnectedMachine = x.SelectedMachine;
                                    }
                                }
                                catch (Exception ex)
                                {
                                    LogManager.Log(ex);
                                    _notificationProvider.ShowError(ex.Message);
                                }

                                InvalidateRelayCommands();
                            }
                        });
                    }
                    else
                    {
                        using (NotificationProvider.PushTaskItem("Connecting to " + x.SelectedMachine.ToString() + "..."))
                        {
                            try
                            {
                                await x.SelectedMachine.Connect();
                                ApplicationManager.ConnectedMachine = x.SelectedMachine;
                            }
                            catch (Exception ex)
                            {
                                LogManager.Log(ex);
                                _notificationProvider.ShowError(ex.Message);
                            }

                            InvalidateRelayCommands();
                        }
                    }

                    InvalidateRelayCommands();
                }

                InvalidateRelayCommands();
            });
        }

        /// <summary>
        /// Navigates to the home screen.
        /// </summary>
        private void Home()
        {
            StartModule(null);
        }

        /// <summary>
        /// Starts the specified module.
        /// </summary>
        /// <param name="module">The module.</param>
        internal void StartModule(IStudioModule module)
        {
            IsMenuOpened = false;

            foreach (var m in StudioModuleLoader.AllModules.Where(x => x != module))
            {
                m.IsLoaded = false;
            }

            if (module != null)
            {
                CurrentModule = module;
                CurrentModule.IsLoaded = true;
                IsModuleLoaded = true;
                View.NavigateToModule(module);
            }
            else
            {
                IsModuleLoaded = false;
                View.NavigateToModule(null);
            }
        }

        /// <summary>
        /// Called when the <see cref="T:Tango.SharedUI.IView" /> is loaded and attached.
        /// </summary>
        protected override void OnViewAttached()
        {
            base.OnViewAttached();
        }

        private void OpenModuleInWindow(IStudioModule module)
        {
            if (module == null) return;

            try
            {
                StartModule(null);

                module.InNewWindow = true;

                var parent = (MainView.Self as MainView).TransitionControl.Controls.SingleOrDefault(x => x.Tag.ToString() == module.Name).Content as Grid;

                var view = parent.Children[0] as FrameworkElement;
                parent.Children.Remove(view);

                ModuleWindowVM vm = new ModuleWindowVM(module, parent);
                ModuleWindow window = new ModuleWindow(this, vm, view);

                window.Closing += (x, y) =>
                {
                    window.grid.Children.Remove(view);
                    parent.Children.Add(view);
                    module.InNewWindow = false;
                };

                window.Owner = MainWindow.Instance;
                window.Show();

                (_applicationManager as DefaultStudioApplicationManager).RegisterOpenedWindow(window);
            }
            catch (Exception ex)
            {
                LogManager.Log(ex, "Error popping out module " + module.Name);
                _notificationProvider.ShowError("Error popping out module " + module.Name);
            }
        }
    }
}